Phase change anti-overflow rapid forming method for composite bottom plate

Abstract

The invention relates to the field of automobile parts, and discloses a composite bottom plate phase change anti-overflow rapid forming method which comprises the following steps: selecting a stamping tray; according to the specification of the stamping tray, a profiling groove is constructed according to profiling parameters; the profiling groove and the stamping tray tightly correspond to each other and are tightly attached to each other to quickly form an assembly structure, round protrusions are arranged on the profiling groove, and the number and the shape of the round protrusions are consistent with those of bolt holes in the stamping tray; the number and the shape of the profiling windows are consistent with those of the windows on the stamping tray; and the combined body structure is fed into a pressing machine to be subjected to mold pressing according to technological parameters, the combined body structure is taken out and separated after mold pressing, and the combined body structure is put into the next period to be used after the profiling groove is cleaned. Rapid forming of the stamping tray in a profiling mode is achieved, so that overflowing of the stamping tray due to phase change of resin or glass fibers in the mold pressing process is avoided, the sealing efficiency is improved, and the technological process is reduced.

Description

Technical Field

[0001] The present invention relates to the field of automotive parts, and particularly to a rapid prototyping method for a composite floor with phase change anti-overflow. Background Art

[0002] In the current field of composite automotive parts, there is a composite stamping tray, which is a battery tray for new energy vehicles. It is the framework of the battery system and can provide anti-impact, anti-vibration and protection for other systems. Its production process requires laying a layer of composite material on one side of the electrophoresed stamping tray (steel plate), and then putting it into a press for molding. There will be pre-drilled bolt holes, window shapes, etc. on the steel plate.

[0003] Among composite automotive parts based on composite materials, the composite stamping tray is mainly used as the battery tray of new energy vehicles. It is the framework of the battery system and can provide anti-impact, anti-vibration and protection for other systems.

[0004] In the production process, it is necessary to lay a layer of composite material on the surface of the electrophoresed stamping tray (steel plate), and then through press molding to make it finally formed. In the specific process, the difficulty lies in that under the high pressure and high temperature of the press, the resin and glass fiber in the composite material will have a process from solid state to liquid state, and then from liquid state to solid state. When its phase state changes to liquid state, the resin and glass fiber will overflow from the bolt holes and window shapes opened on the surface of the stamping tray. Finally, under the action of the press, these overflowed resin and glass fiber turn into solid state, resulting in overflowing glue at the bolt holes and window shapes on the product surface, affecting the appearance and dimensional performance of the product.

[0005] If laser hole opening and window opening are carried out after the stamping tray is formed, the electrophoretic paint on the surface of the stamping tray will be melted by the high temperature of the laser. At this time, the adhesion of the stamping tray will become poor, affecting the painting quality. For example, the inner layer, depression, weld and other parts of the workpiece cannot obtain a uniform and smooth paint film, and the service life cannot be extended. Therefore, only the process of opening holes first and then electrophoresing can be adopted.

[0006] To solve the overflow problem, the existing technical methods generally stick special high-viscosity high-temperature tapes on the surface of the electrophoresed stamping tray, seal the entire surface of the stamping tray steel plate, and place a silicone hole pad at each bolt hole position to block it, so as to avoid the overflow of liquid resin and glass fiber. However, this process requires a large amount of high-temperature tapes, and the product quality fluctuates with the viscosity of the high-temperature tapes. If the viscosity is too low, there will be gaps, and there is still a risk of product overflow. If the size of the silicone pad used to seal the bolt hole is too large, the silicone pad cannot be completely inserted or partially inserted, resulting in the phenomenon of overflowing glue folds. If the size is too small, there will be gaps and holes, and even the risk of falling, which will also lead to the phenomenon of overflowing glue. Summary of the Invention

[0007] The object of the present invention is to provide a rapid prototyping method for preventing overflow by phase change of a composite bottom plate, so as to solve the technical problems such as easy glue overflow during pressing of a stamping tray and related derivative technical problems in the prior art.

[0008] To solve the above technical problems, the present invention specifically provides the following technical solutions:

[0009] The present invention provides a rapid prototyping method for preventing overflow by phase change of a composite bottom plate, including the following steps:

[0010] Select a stamping tray;

[0011] According to the specifications of the stamping tray, a profiling groove is constructed according to profiling parameters.

[0012] The profiling groove and the stamping tray are tightly corresponding and closely fitted to quickly form a combined structure. Among them, the following are provided on the profiling groove:

[0013] Circular protrusions, the number and shape of the circular protrusions are the same as the bolt holes on the stamping tray;

[0014] Profiling windows, the number and shape of the profiling windows are the same as the window shapes on the stamping tray;

[0015] The combined structure is sent into a press for molding according to process parameters. After molding, the combined structure is taken out and separated. After cleaning the profiling groove, it is put into the next cycle for use.

[0016] As a preferred scheme of the present invention, the profiling parameters include shaping parameters, quantity parameters and dimension parameters.

[0017] As a preferred scheme of the present invention, the rapid formation method of the combined structure is:

[0018] The profiling groove and the stamping tray are respectively placed on two production lines, and the profiling groove and the stamping tray are delivered according to the same operating cycle to ensure that the profiling groove and the stamping tray reach the forming station synchronously;

[0019] At the forming station, it is grabbed and directly fitted by an automated mechanism;

[0020] After the automated mechanism completes the fitting, it is preliminarily pressed by touch pressing to form the combined structure.

[0021] As a preferred scheme of the present invention, it further includes quality inspection according to the shaping parameters after the combined structure is rapidly formed; the quality inspection standard is that the shape of the profiling groove is higher than the surface of the stamping tray, and the height difference is not less than 1 mm.

[0022] As a preferred embodiment of the present invention, the shaping parameters include circular protrusions and profiling windows, and the inner contour of the profiling groove conforms to the outer periphery of the stamping tray.

[0023] As a preferred embodiment of the present invention, the circular protrusions can penetrate through the bolt holes; the profiling windows conform to the window shaping, and the profiling windows can penetrate through the window shaping.

[0024] As a preferred embodiment of the present invention, the quantity parameters include:

[0025] The number of the circular protrusions is the same as the number of bolt holes on the stamping tray; the number of the profiling windows is the same as the number of window shapings on the stamping tray.

[0026] As a preferred embodiment of the present invention, the dimension parameters include: the area ratio of the profiling groove to the stamping tray is (0.92 - 0.95):1; the thickness ratio of the profiling groove to the stamping tray is (1.5 - 2):1; the diameter of the circular protrusions is 0.2 mm - 0.4 mm larger than the diameter of the bolt holes; the area ratio of the profiling windows to the stamping windows is (1.05 - 1.1):1.

[0027] As a preferred embodiment of the present invention, the profiling groove is made of silicone rubber with a Shore hardness of 20 - 30 degrees.

[0028] The present invention has the following beneficial effects compared with the prior art:

[0029] (1) Through the profiling part that conforms to the stamping tray with specific profiling parameters, the present invention forms an integrated combined structure. The profiling groove conforms to the stamping tray according to specific profiling parameters. The material homogeneous temperature of the profiling groove has good connection effect, reduces the risk of glue overflow, and the profiling part is integrally formed with low risk of part dropping and is not easy to get stuck during the production process, solving the "stuck" problem of production efficiency in the production process.

[0030] (2) In the production of the same specification using an assembly line, the present invention quickly closes the bolt holes and window shapings on the stamping tray in a profiling manner and can be quickly removed after forming. On the one hand, the efficiency of closing and demolding is high, improving the working efficiency of the laying process. On the other hand, the closing error is small, which is beneficial to quality control.

[0031] (3) Through the quick die pressing closing and demolding of the stamping tray, the present invention does not require steps such as fitting, plugging holes, and buckling molds, reduces the process flow, speeds up the production rhythm, and can achieve batch production. Description of the Drawings

[0032] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary. For those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained based on the provided drawings.

[0033] Figure 1 It is a schematic structural diagram of the profiling groove provided by the present invention;

[0034] Figure 2 It is a schematic flow chart of the rapid prototyping method for preventing overflow by phase change of the composite bottom plate provided by the present invention.

[0035] The reference numerals in the figure are respectively represented as follows:

[0036] 1 - Profiling groove; 2 - Circular protrusion; 3 - Profiling window. Specific embodiments

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] As Figure 1 shown, the present invention further provides a rapid prototyping method for preventing overflow by phase change of a composite bottom plate, including the following steps:

[0039] (1) Select a stamping tray;

[0040] (2) According to the specifications of the stamping tray, construct a profiling groove according to the profiling parameters;

[0041] (3) Tightly align and closely fit the profiling groove with the stamping tray to quickly form a combined structure. Among them, circular protrusions and profiling windows are provided on the profiling groove. The number and shape of the circular protrusions are the same as the bolt holes on the stamping tray, and the number and shape of the profiling windows are the same as the window shapes on the stamping tray;

[0042] (4) Send the combined structure into a press for molding according to the process parameters. After molding, take out the combined structure and separate it, clean the profiling groove and put it into the next cycle for use.

[0043] In the specific production process, in order to ensure that the stamping tray can be rapidly prototyped with the profiling groove 1, the present invention further optimizes the profiling parameters between the stamping tray and the profiling groove 1. The profiling parameters include profiling parameters, quantity parameters, and dimension parameters.

[0044] Specifically, in order to avoid damage to the mold when it is pressed down due to excessive hardness, such a profiling groove is made of silicone rubber with a Shore hardness of 20-30 degrees and a thickness of 3-5 mm.

[0045] Preferably, the thickness of the profiling groove 1 is selected according to the thickness of the composite stamping tray. The thickness of the silicone rubber is generally between 1.5 and 2 times the thickness of the composite stamping tray, that is, the combined thickness of the dp780 steel plate and the composite material.

[0046] The depth of the profiling groove 1 is determined according to the shape of the composite stamping tray. The size of the internal groove is slightly smaller than that of the composite stamping tray, and the approximate ratio is between 0.92 and 0.95, which can make the stamping tray fit tightly with the silicone rubber groove. This can not only solve the problem of glue overflow, but also is not easy to crack, and the risk of glue overflow decreases.

[0047] The number and shape of the circular protrusions 2 are the same as the bolt holes on the stamping tray. In order to prevent glue overflow, the diameter of the circular protrusions 2 is slightly larger than the diameter of the bolt holes on the stamping tray, about 0.2 mm - 0.4 mm.

[0048] Due to the change in the coefficient of thermal expansion of silicone rubber itself, the larger the diameter of the bolt hole, the greater the increase in the diameter of the circular protrusion 2, and the height of the circular protrusion 2 is 1 mm higher than the surface of the stamping tray. This can avoid the phenomenon that the size of the circular protrusion 2 is too large to fit with the bolt hole, resulting in glue overflow and wrinkles, and also avoid the situation where the size of the circular protrusion is too small, resulting in gaps and holes. It also avoids the risks of the silicone rubber pad falling off and the worker manually stuffing the silicone rubber pad incorrectly, which may cause glue overflow and coagulation, and improves the working efficiency of the laying process.

[0049] The profiling window 3 is slightly larger than the stamping tray window, and the expected ratio is about 1:1.05 - 1.1. Select an appropriate ratio according to the size of the window, and the height of the profiling window 3 is 1 mm higher than the surface of the stamping tray window, which can effectively prevent glue overflow at the window part and eliminate the process step of using high-viscosity high-temperature tape on the entire surface of the stamping tray.

[0050] The existing composite stamping tray forming method requires the use of high-temperature tape and silicone pads, including the following steps: cutting the high-temperature tape for composite stamping tray shaping, sticking the high-temperature tape to the bottom of the composite stamping tray, cutting the silicone hole pads into appropriate shapes, stuffing the silicone hole pads into the bolt holes, limiting the height of the silicone hole pads, and performing die pressing; after die pressing, tearing off the high-temperature tape and picking out the silicone hole pads one by one. The defects of the above process are as follows: 1. The product quality fluctuates with the viscosity of the high-temperature tape. If the viscosity is too low, there will be gaps and the risk of product overflow; for the silicone pads used in the bolt holes, if the size is too large, the silicone pads cannot be completely stuffed or only partially stuffed, or due to the loss of the silicone hole pads, the phenomenon of overflow and wrinkles will occur; 2. The silicone hole pads are prone to loss due to their small size and thinness, resulting in the problem of "jamming" during the production process; 3. Workers manually stuff and pick out the silicone pads, with low work efficiency and long production cycle.

[0051] The forming method provided by the present invention directly presses the stamping tray into the profiling groove to form an integral combined structure. The profiling groove and the stamping tray are shaped according to specific profiling parameters. The profiling groove material has a homogeneous temperature, good connection effect, reduced risk of overflow, low risk of part dropping, and is not easy to "jam" during the production process.

[0052] After die pressing the combined structure, separate the two. When the stamping tray falls off, its bolt holes and window shapes can directly fall off from the circular protrusions and profiling windows, shortening the production cycle.

[0053] The profiling groove can be used again.

[0054] Compared with the above artificial production line, the rapid forming method for preventing overflow of the composite bottom plate during phase change has the following advantages: (1) low risk of overflow; (2) the hole and window parts are integrally formed and not easy to lose; (3) the combination separation is convenient, the operation process is less, and the production cycle is short.

[0055] The method for quickly forming the combined structure is as follows:

[0056] Place the profiling groove and the stamping tray on two assembly lines respectively, and deliver the profiling groove and the stamping tray according to the same operating cycle to ensure that the profiling groove and the stamping tray reach the forming station synchronously;

[0057] At the forming station, grab and directly fit them through an automated mechanism. The steel plate surface of the composite stamping tray faces downwards, and the composite material surface faces upwards. Its windows are aligned, and the fitting is completed using an automated mechanism;

[0058] At this time, the temperature and pressure of the press in the forming station reach the set process parameters, and through touch pressing, a preliminary press is performed to form a combined structure;

[0059] After the molding is completed, take out the molded product from the profiling groove and clean the silicone rubber for the next use.

[0060] Compared with the existing production processes such as tape bonding and silicone insertion, the rapid formation method of the composite structure can improve production efficiency. The bolt holes and window shapes on the stamping tray can be quickly sealed only through one-step bonding of the automated mechanism, which avoids the overflow of resin or glass fiber phase change during the molding process.

[0061] The mold closing cycle of the composite stamping tray is controllable. In the production of the same specification, rapid automated sealing is carried out in a pipeline manner. After the forming station reaches the standard process parameters, the automated mechanism transports the composite structure to the forming station, realizing pipeline operation. Since the profiling groove and the stamping tray are conforming, they can be pressed in one step, and the sealing efficiency is high; on the other hand, the profiling groove, circular protrusion, and profiling window are formed integrally and can be separated in one step after the molding is completed, improving the working efficiency of the laying process, reducing the process flow, accelerating the production rhythm, and enabling batch production.

[0062] Secondly, the integrally formed profiling method is not easy to lose parts, which is beneficial to quality control and also solves the "bottleneck" problem of efficiency in the production process.

[0063] The rapid prototyping method disclosed by the present invention can quickly seal the bolt holes and window shapes on the stamping tray by means of profiling, thereby avoiding the overflow of resin or glass fiber phase change during the molding process.

[0064] In order to avoid the phenomenon of glue overflow and wrinkles caused by the oversize of the circular protrusion 2 and inability to fit with the bolt hole, and at the same time to prevent glue overflow at the window part, the process step of using high-viscosity high-temperature tape on the entire surface of the stamping tray is omitted. After the composite structure is rapidly formed, quality inspection is carried out according to its modeling parameters;

[0065] The quality inspection standard is that the shape of the profiling groove is higher than the surface of the stamping tray, and the height difference is not less than 1 mm.

[0066] In the rapid prototyping method for preventing overflow during the phase change of the composite bottom plate, by detecting the height difference between the profiling groove and the stamping tray, the probability of material glue overflow can be better controlled during stamping. The detection method is relatively simple, which is beneficial to quality control and reduces the rejection rate.

[0067] As Figure 2 shown, the present invention provides a profiling groove, which can be used for the forming of a composite bottom plate of steel plate and glass fiber.

[0068] Taking the composite stamping tray as an example, during use, the composite stamping tray is inserted into the profiling groove 1. The profiling groove 1 can replace the high-temperature tape in the prior art and seal the steel surface of the composite stamping tray. This profiling groove 1 can tightly correspond to and closely fit with the stamping tray to quickly form a combined structure. The number and shape of the circular protrusions 2 on the profiling groove 1 are the same as those of the bolt holes on the stamping tray, and the number and shape of the profiling windows 3 on the profiling groove 1 are the same as those of the window shapes on the stamping tray.

[0069] The usage method of the profiling groove 1 is as follows: Use an automated mechanism to grasp the profiling groove 1 and tightly fit it with the stamping tray, and tightly correspond and fit the profiling groove 1 with the stamping tray; Send the combined structure into the press and perform die pressing according to the process parameters. The circular protrusions 2 are fitted into the bolt holes, and the profiling groove 1 is engaged in the profiling window; After die pressing, take out the combined structure and separate it, clean the profiling groove and put it into the next cycle of use to achieve the stamping tray.

[0070] The main material of the profiling groove 1 is silicone rubber with a Shore hardness of 20 - 30 degrees, and there are fixed proportional parameters between the profiling groove 1, the circular protrusions 2, the profiling windows 3 and the stamping tray. During the stamping process, the composite stamping tray is fitted in the profiling groove. The circular protrusions 2 can be buckled into the bolt holes during use, playing a role in preventing glue overflow.

[0071] The present invention specifically discloses using silicone rubber with a Shore hardness of 20 - 30 degrees as the main material, selecting an appropriate thickness as the sealing plate, constructing the profiling groove according to the fixed profiling parameters according to the style of its stamping tray, and then making the bolt holes and windows inside it into profiling protrusions. The size and thickness of the profiling protrusions have a certain proportional parameter with the bolt holes and windows of the stamping tray. Place the stamping tray with one side paved with composite material, with the steel plate surface facing down and the composite material side facing up, into the groove, and finally put it into the press for die pressing. After die pressing is completed, take out the product placed inside the silicone rubber groove, thus completing the die pressing.

[0072] In this embodiment, an integrally formed forming die is adopted, and the proportional parameters between the die and the workpiece are preferably selected, replacing the high-temperature tape required during the die pressing process of the stamping tray, achieving the sealing of the steel plate and preventing the resin and glass fiber from overflowing onto the steel plate surface; Secondly, an integrally formed convex structure is adopted, replacing the silicone gasket, and at the same time standardizing the size, height, etc. of the convex structure, which can seal the bolt holes and windows on the composite stamping tray, preventing the resin and glass fiber from overflowing inside and outside the bolt holes and windows.

[0073] Based on the fact that the thermal expansion coefficient of silicone rubber at around 150 to 160 degrees is approximately 3%, when the mold temperature in the press reaches around 145 degrees, the silicone rubber will expand to fill the mold gaps, preventing the resin from flowing inside the mold and forming overflow glue. Therefore, silicone rubber with higher heat resistance, excellent deformation quality, and appropriate hardness needs to be selected.

[0074] The molding process parameters can be selected as follows: mold temperature of 130°C - 150°C; the mold pressure is selected according to the thickness ratio between the stamping tray and the composite material layer and the projected area of the mold. The specific selection of the mold pressure can refer to the formula T = S * F1 * F2 / F 表 (where T represents: the tonnage of the press; S represents: the horizontal projected area of the product; F1 represents: the unit pressure required for the product; F2 represents: the rated gauge pressure of the press; F 表 represents: the molding pressure, that is, the gauge pressure.)

[0075] Through the rapid prototyping method for preventing overflow by phase change of the composite bottom plate in this embodiment, the rapid molding of the stamping tray is realized. The bolt holes and window shapes on the stamping tray are quickly sealed by profiling, so as to prevent the overflow of resin or glass fiber due to phase change during the molding process, eliminating the steps of taping and plugging holes, improving the working efficiency of the laying process, solving the "bottleneck" problem of efficiency in the production process, accelerating the production rhythm, and enabling batch production.

[0076] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present application, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present application.

Claims

1. A rapid prototyping method for phase change and overflow prevention of a composite bottom plate, characterized in that: The steps include: Choose a stamped pallet; According to the specifications of the punching tray, constructing the profiling groove according to the profiling parameters; The profiling groove is closely matched with the stamping tray and closely fits to quickly form a combined structure, wherein the profiling groove is provided with: Circular protrusions, the number and shape of the circular protrusions are consistent with the bolt holes on the stamping tray; Contoured windows, the number and shape of which are consistent with the window shapes on the stamping tray; The combined structure is sent into a press to be molded according to process parameters, and after the molding, the combined structure is taken out and separated, and the contoured groove is cleaned and then put into use in the next cycle.

2. A rapid prototyping method for phase change and overflow prevention of a composite bottom plate according to claim 1, characterized in that: The profiling parameters include modeling parameters, quantity parameters and size parameters.

3. A rapid prototyping method for preventing overflow of a composite bottom plate phase change according to claim 2, characterized in that: The rapid formation method of the assembly structure is as follows: Placing the profiling groove and the punching tray on two production lines respectively, and delivering the profiling groove and the punching tray according to the same operation cycle, ensuring that the profiling groove and the punching tray arrive at the forming station synchronously; Grasping and directly bonding at the forming station by an automated mechanism; After the lamination is completed, the automated mechanism performs preliminary pressing by touch pressing to form the combined structure.

4. A rapid prototyping method for phase change and overflow prevention of a composite bottom plate according to claim 3, characterized in that: It also includes performing quality inspection according to the modeling parameters of the combined structure after rapid prototyping; The quality inspection standard is that the shape of the contoured groove is higher than the surface of the stamping tray, and the height difference is not less than 1 mm.

5. The rapid prototyping method for phase change and overflow prevention of a composite bottom plate according to claim 2, characterized in that: The modeling parameters include a circular protrusion and a contoured window, and the inner contour of the contoured groove follows the outer periphery of the stamping tray.

6. A rapid prototyping method for phase change and overflow prevention of a composite bottom plate according to claim 5, characterized in that: The circular protrusion can pass through the bolt hole; The profiling window follows the shape of the window, and the profiling window can penetrate the shape of the window.

7. A rapid prototyping method for phase change and overflow prevention of a composite bottom plate according to claim 2, characterized in that: The quantitative parameters include: The number of the circular protrusions is consistent with the number of bolt holes on the stamping tray; The number of the contoured windows is consistent with the shape of the windows on the stamping tray.

8. The rapid prototyping method for phase change and overflow prevention of a composite bottom plate according to claim 2, characterized in that: The size parameters include: The ratio of the area of ​​the profiling groove to the area of ​​the punching tray is (0.92-0.95):1; The thickness of the contoured groove is (1.5-2):1 compared to the thickness of the stamping tray; The diameter of the circular protrusion is 0.2 mm to 0.4 mm larger than the diameter of the bolt hole; The ratio of the area of ​​the contoured window to the area of ​​the stamping window is (1.05-1.1):

1.

9. The rapid prototyping method for phase change and overflow prevention of a composite bottom plate according to claim 1, characterized in that: The contoured groove is made of silicone rubber with a Shore hardness of 20-30 degrees.

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